During the annual meeting of the United Nations General Assembly in New York City, on Wednesday, September 21, 2016, UN Secretary-General Ban Ki-moon announced that more than 55 countries have formally joined the Paris Agreement on climate change, officially crossing one of the two thresholds required to bring the Agreement into force. At the annual meeting, 31 additional countries deposited their instruments of ratification for the Agreement, bringing the total to 60 countries that together represent more than 47.5% of global greenhouse gas emissions. Earlier this month, China and the United States, the world’s two largest greenhouse gas emitters, joined the Agreement.

The Paris Climate Agreement was adopted by the 195 Parties to the UN Framework Convention on Climate Change (UNFCCC) at a conference known as COP21 in December 2015. The Paris Climate Agreement seeks to limit global temperature rise to well below 2 degrees Celsius, and to strive for 1.5 degrees Celsius. The Paris Climate Agreement was signed on April 22, 2016, by 175 countries at the largest, single-day signing ceremony in history. It will enter into force 30 days after at least 55 countries, accounting for 55% of global greenhouse gas emissions, deposit their instruments of ratification. Following today’s UN meeting, formal approval from countries representing 7.5% in global emissions is still needed.

Usually, international treaties of this size and complexity take years to come into effect, while the Paris Climate Agreement is close to achieving full legal force only 9 months after it was adopted. At least some of the urgency behind the ratification of the Agreement is the fact that Republican presidential candidate Donald Trump has vowed to pull the United States out of the Paris Climate Agreement if he is elected. If the Agreement comes into full legal force before the next president takes office, it would take four years for the United States to withdraw under the formal procedures of the Agreement, and the United States would be bound by the Agreement in the interim.

More information about the Paris Climate Agreement and a video of Secretary-General Ban Ki-moon’s remarks is available here.